Abstract
An organic light-emitting diode containing titanyl phthalocyanine (TiOPc) and tris-(8-hydroxy quinoline) aluminum (Alq3) layers has been fabricated. The device exhibits green emission from the Alq3 emissive layer under ambient conditions. Below the turn-on voltage, the green emission is instantaneously switched on by laser irradiation at 650 nm, indicating that the device can be used as a red-to-green light converter. Above the turn-on voltage, the green emission is greatly enhanced by laser irradiation, while the current-voltage characteristics are significantly modified. Amplification factors of the emission intensity as well as the current density upon laser irradiation are found to greatly depend on the TiOPc layer thickness. The TiOPc layer acts as a hole generation layer rather than as a buffer layer.